I lied about university and cost my parents loads of money...

I began uni in 2010, I decided I didn't like it so didn't really bother going in, my parents paid my rent, I couldn't tell them I wasn't enjoying it because I couldn't face the dissapointment. I went back in 2nd year to live in a house with my friends I had met in first year, seeing as I hadnt got into second year I never went in, I still just couldnt tell my parents I didnt like it. I can't afford the tax that I got because im not a student, but I cant tell my parents I wasted so much money. They think im going back next year, but i really can't. I don't know how to tell them I dropped out 2 years ago.